import React, {Component} from 'react';
import CommentAdd from '../comment-add/comment-add'
import CommentList from '../comment-list/comment-list'

export default class App extends Component {

    // 给组件对象指定state属性
    state = {
        comments: []
    }

    // 添加评论
    addComment = (comment) => {
        // 获取当前的数据
        let {comments} = this.state;
        comments.unshift(comment);
        // 更新状态
        this.setState({comments})

    }

    // 删除指定评论
    deleteComment = (index) => {
        let {comments} = this.state;

        comments.splice(index, 1); // splice() 增删改都能做
        // comments.splice(index, 0,{}); // 增加
        // comments.splice(index, 1,{}); // 替换
        // 更新状态
        this.setState({comments})
    }

    componentDidMount() {
        // 异步获取数据
        setTimeout(() => {
            this.setState({
                comments: [
                    {username: "Tom", content: "React挺好的！"},
                    {username: "Jack", content: "React太难了"}
                ]
            })
        }, 1000)
    }

    render() {
        const {comments} = this.state;
        return (
            <div>
                <header className="site-header jumbotron">
                    <div className="container">
                        <div className="row">
                            <div className="col-xs-12">
                                <h1>请发表对React的评论</h1>
                            </div>
                        </div>
                    </div>
                </header>
                <div className="container">
                    <CommentAdd addComment={this.addComment}/>
                    <CommentList comments={comments} deleteComment={this.deleteComment}/>
                </div>
            </div>
        )
    }
};